INNOVATIVE HIGH-AIRFLOW SMOKEHOUSE DESIGN WITH NOVEL METHOD OF CONTROLLING AIRFLOW TO COOK FASTER & TO REDUCE TEMPERATURE & COLOR VARIATION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: SMALL BUSINESS GRANT
• Reporting Frequency: Annual
• Accession No.: 0228897
• Grant No.: 2012-33610-19500
• Proposal No.: 2012-00093
• Project Start Date: May 15, 2012
• Project End Date: Jan 14, 2013
• Grant Year: 2012
• Program Code: [8.5]- Food Science & Nutrition

Recipient Organization
HansonTech
809 3rd St
Hudson,WI 54016

Performing Department
(N/A)

Non Technical Summary
Industrial smokehouses are large forced-air convection batch ovens used to cook and smoke meat products such as bacon, ham, bologna, whole turkeys, chicken breast, snack sticks, jerky, smoked sausage, hotdogs, sliced luncheon meats, and other smoked meats. These huge smokehouses are crucial to the operation of the American meat industry, yet in the past two decades, the design of these ovens has stagnated. Evolutionary improvements have included improved construction materials, computer controls, higher efficiency gas burner and electric motors, and lower cost variable-speed fan drives. Incredibly, however, the cooking performance of smokehouses is virtually the same today as it was 25 years ago. Even more remarkable, the market leading smokehouse manufacturers all use air-handling systems that are very similar in function, and therefore very similar in performance. As such, regardless of the age or brand of smokehouse, most smokehouses in the field today have pretty much the same capabilities and performance. So if a company buys a brand-new smokehouse and installs it next to a 25 year-old one, the owner of the new smokehouse will be surprised to find that although the new oven has a modern control system, increased corrosion resistant, and higher efficiency components, when it comes to its performance in cooking smoked meats, the beat-up old oven will cook just as fast as the new one. Along with the universally anemic cooking performance of modern smokehouse designs, these out-dated air-handling systems create significant color, yield, and temperature variation. Field data show that yields typically vary as much as 1.5% within a single load, and this yield variation costs the industry hundreds of millions of dollars each year. Product temperatures routinely vary as much as 8-16 degrees F within a batch, creating a food safety risk of under-cooked product. To make sure that the products in the coldest areas of a smokehouse are fully cooked, oven operators must over-cook the entire load, resulting in food safety risks, reduced throughputs, and lost yield that again cost the industry hundreds of millions of dollars each year. True innovation in smokehouse air-handling performance has been stagnant for decades, but the opportunity we see is to design an innovative new air-handling system for smokehouses that would allow users to produce smoked meats safer, better, and faster at lower cost -- both to improve efficiency of this multi-billion dollar industry and to advance consumer food safety. Our approach is to design an advanced new air-handling system that could be installed as an improved design on new smokehouses or retrofitted onto old ones, thus moving the food safety and manufacturing efficiency of the meat industry forward for both new and existing ovens without requiring the massive capital investment that would be required for a full replacement of existing smokehouses. Preliminary field trials have shown that our new air-handling concept has the potential to reduce cooking times by 10-20% and cut temperature variation in half.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
501	3220	2020	100%

Knowledge Area
501 - New and Improved Food Processing Technologies;

Subject Of Investigation
3220 - Meat-type chicken, live animal;

Field Of Science
2020 - Engineering;

Keywords

smokehouse

meat

cooking

smoking

air handling

airflow

oven

meat industry

Goals / Objectives
The basic designs of industrial smokehouses for smoked meats have remained functionally unchanged for over 25 years. Although some components such as control systems and cabinet designs have evolved, the cooking performance of smokehouses has remained essentially unchanged. Cooking times have only marginally improved, and chronic problems with uneven temperatures and variable quality continue to plague users, creating waste, inefficiency, and potential for undercooking. This SBIR application is the first step in developing a next generation smokehouse. The project objectives are to -- 1. Develop a design and a 3-D CAD model for an efficient air-handling system that will deliver significantly higher airflow volumes than existing smokehouse air-handling systems. 2. Develop a design and a 3-D CAD model for an innovative new oscillating airflow system that will enable more precise and flexible control of the air in a smokehouse. 3. Develop a design and a 3-D CAD model of a the new air inlet slots that will sweep the air from side-to-side in the oven at optimal speeds to minimize color, yield, and temperature variation. Build and conduct preliminary tests of a manually-operated version of the new air-inlet slots retrofitted onto an existing oven. Test, de-bug and prove the effectiveness of the new design. Expected outcomes for this project are a fully developed 3-D CAD model of the smokehouse, and completion of the design and manual testing of the new air inlets.

Project Methods
We will develop 3-D models of an innovative new high-airflow air-handling system with innovative new air inlets, and conduct preliminary tests of this design using the 3-D models as well as hand-operated inlet slots retrofitted onto an existing oven. This proof-of-concept testing on the hand-operated components will be conducted on an existing production-scale smokehouse. We will use recording vane anemometers to objectively measure the effectiveness of the new air-inlet design, and a fog machine to visually observe and video-record the airflow patterns for the new design vs conventional systems. We will engineer and construct a 3-D CAD model of the high-airflow air-handling system in a SolidWorks CAD system. This 3-D model will be used to test and validate the design principles of the system and to examine the fit-up and scalability for various sizes of ovens. We will also engineer and construct a detailed 3-D CAD model of the new air-inlet slots in SolidWorks CAD. Manually-operated versions of the new air-inlet slots will be fabricated and retrofitted onto an existing production-scale smokehouse. The prototype slots will be hand-operated for testing. Extensive airflow data will be collected using recording vane anemometers to determine the effectiveness and feasibility of the new design. A fog machine will be used to visually evaluate and video-record the effectiveness of the new design. The test system will be modified and refined as necessary to optimize performance. We are optimistic that this SBIR Phase I proof-of-concept work will lead an innovative new smokehouse design in a market that is starved for innovation. The meat industry is a huge business in the United States, but for decades, the anemic air-handing systems used on conventional smokehouses have hamstrung production performance and hurt industry efficiency. We believe that commercialization and widespread adoption of our innovative new high-airflow, high-efficiency, precision-controlled air-handling system will lead to innovative new smokehouse designs that promote higher throughputs, more consistent quality, and reduced food safety risk for smoked meat products. This air-handling knowledge will be combined with processing know-how to improve smokehouse performance, and then this knowledge will be transferred to the industry through web videos, industry workshops, trade-show technical sessions, and university teaching workshops.

Progress 05/15/12 to 01/14/13

Outputs
OUTPUTS: We used SolidWorks 3-D modeling software to develop a 3-D CAD model of a new high-volume air-handling kit that doubled the volumetric airflow rate of conventional systems. Part of the model was a new, simpler oscillating airflow system designed to sweep the air from side-to-side in the process cabinet much like conventional systems, but with fewer moving parts. The oscillating airflow system in the new model was also designed to have independently controlled, variable-width supply slots designed to enable precision control over the location and dwell times of the air stream in the cabinet.conventional designs. The base CAD model was used to design air kits for small and large smokehouses to evaluate scalability of the design. A 66% scale-model was designed and fabricated to test the principles of the new design. The scale-model was built with clear plastic walls so that we could see into the cabinet. Scale-model racks were placed in the cabinet to simulate actual meat products. Several experiments were conducted to manually test the individual components and combination of components for effect on the uniformity and velocity of the air at various locations in the cabinet. Burst-mode photographs, video, and recording anemometers were used to record the results of those test runs. Currently, these outputs are being held as proprietary information, but our intent is to incorporate the new designs into new oven designs and into retrofit designs for existing equipment. Our findings will be disseminated within the meat industry through client discussions, industry trade shows, industry workshops, trade magazines, published books, book chapters, and academic workshops. PARTICIPANTS: The project was conducted by Robert Hanson, principal investigor, and Noel Johnson, co-PI. The prototype was built and tested in the shop of Simply Manufacturing, Inc. Controls engineering services were provided as in-kind support by Powis Corporation. TARGET AUDIENCES: The primary target audience served by this project would be manufacturers of cooked and smoked ready-to-eat meat products. This list would include very small, small, medium, and large manufacturers of RTE meats. Other primary target audiences would be meat industry suppliers of smokehouses, smokehouse controls, and smokehouse renovation services. PROJECT MODIFICATIONS: The project was conducted as planned except for the prototype testing. The original plan was to test manually-operated supply slots by modifying an existing one-rack smokehouse. However, after a detailed evaluation of costs, we discovered that it would actually cost less to build a small scale-model prototype than to modify an existing oven for testing, and then restore it to original condition for sale. Along with being less costly, the new prototype had the additional advantages in that we could build it out of clear plastic for visual analysis and that it could be built to test the high volume air-kit as well as the variable-width supply slots. Finally, we were able to design the new prototype with a slatted return duct that allowed us to test various configurations of return openings -- a design decision that ultimately led to the significant discovery on the extended-return duct design.

Impacts
We used the CAD models to design a novel new air-handling design that we believe will be more efficient, simpler, and more durable than conventional air kits. The CAD model demonstrated the design was scalable from small to large smokehouses. The CAD model was also used to demonstrate the design of retrofit components for upgrading existing smokehouses in the field. The core elements of the CAD design were incorporated into the two-thirds scale prototype for testing. The prototype testing generated both expected and unexpected results. As expected, the new air-kit was effective in delivering double the volumetric airflow of a conventional design at a much lower static pressure. The variable-width supply slots worked well in delivering the expected sweeping action of the air-stream in the cabinet, but were even more effective than expected -- giving unexpectedly precise control over the direction and dwell time of the high speed air-stream in the cabinet. During our prototype testing, another unexpected result was the discovery a strong Venturi effect that pull the air completely across the full width of the cabinet. When one supply slot was fully open and the other was closed, the Venturi effect actually pulled the air across the cabinet with only a slip-stream pulled up into the return duct. This discovery led us to develop a re-designed return duct that extended the duct down into the cabinet to reduce the Venturi effect. The new extended return duct not only reduced the pull of the Venturi, it also unexpectedly produced the most uniform, highest velocity airflow of all the test runs. The anemometer and fog machine data showed that the extended-return duct favored pulling air through the historically "cold-spot" that exists at the top-center of conventional designs -- generating the most uniform airflow and higher velocity air through all areas of the cabinet, including the "cold-spot." This discovery was an unexpected and exciting result, especially given that an extended return duct would be a relatively straightforward, high-impact design that would work for most existing smokehouses. Using the extended-return duct in combination with the variable-width supply slots created much more uniform air velocities through the "cold-zone" at the top-center of the cabinet than conventional designs. Also, when used in further combination with the new high-volume air kit, the air velocities were measurably more uniform and almost double those of conventional designs. If these new changes are incorporated into new ovens and retrofit smokehouses, we believe that these new components will lead to breakthrough new designs that are more efficient, more durable, simpler, faster cooking, more uniform, and higher yielding than conventional designs.

Publications

• No publications reported this period